Method of forming and knurling metal bodies



0. u. ZERK METHOD OF FORMING AND KNURLING METAL BODIES 3 Sheets-Sheet 1 A ril 8, 1930.

Filed April 16 1923 u: 4 O a oscAR UZERK. IA'I/ENTOR.

By W V" r I H x s A TTORNEYS April 3, 1930. 0, U, Z K 1,753,258

METHOD OF FCRMING AND KNURLING METAL BODIES Filed April 16, 1923 3 Sheets-Sheet a V 31 1 i i I LL-LLLU-L L. a

HIS A TTORNEY I 9 blank the same Fatented Apr. 8, 1930 OSCAR U. Em NOW BY JUDICIAL CHANGE OF NAME OSCAR ULYSSES ZEBK, F

CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 ALEMI'IE CORPORA- EIGN, 0F CHICAGO, ILLINOIS, A CORFORATION OF DELAWARE METHOD OF FORMING AND KNUELING METAL BODIES Application filed April 16,

This invention relates to improvements in the method of forming and knurling sheet metal bodies.

An object of my invention is to provide an improved method of forming and knurling sheet metal bodies which consists in pressing the blank through a die with a mandrel.

Another object of my invention is to provide an improved method of torming and m knurling a sheet metal article from a blank body during the single operation of pressing the blank body through a die with a mandrel.

Another object of my invention resides in the method of reducing and knurling a hollow sheet metal cylinder by pressing it through a die whereby the blank is formed and elongated in a desired shape.

These and other objects are illustrated in the accompanying drawings, and are set forth in the accompanying specification and claims.

In the drawings Fig. 1 is a longitudinal sectional view through the forming and knurling die andthe blank and also showing a mandrel positioned within the blank just previous to operation; Fig; 2 is a similar section showing the same elements at the finish of the forming and knurling operation; Fig. 3 is a transverse sectional view of the same taken on line 33 of Fig. 2; Fig. 4 is a longitudinal sectional view of a similar arrangement as in Fig. 1 but with a larger blank and a difierently shaped mandrel; Fig. 5 is a similar view of the elements in Fig. 4: taken at the finish of the forming and knurling operation; Fig. 6 is a transverse sectional view taken on line 6-6 of Fig. 5; Fig. 7 is a longitudinal sectional view illustrating a modified type of die and with the mandrel and as in Fig. 2; Fig. 8 is a section similar to that in Fig. 7 showing the finish of the forming and knurlin operation; Fig. 9 is a side elevation of the ished container resulting from the forming and knurling operations; and Fig. 10 is an enlarged view of a section of the knurled container.

Referring to the drawings by characters of reference, A represents a hollow sheet metal body to be formed and knurled, B re resents the forming and knurling die, an

of which is knurled to in the blank and 1923. Serial .El'o. 632,331.

represents the mandrel which is inserted within the hollow body to press it through the die and co-operates with the die in forming the same.

I have illustrated for-reference a hollow cylindrical sheet metal blank, one end of which is reduced and the remaining portion container of a lubricant dispensing apparatus. lit is to be understood that blank bodies of other shapes to be used for this and other purpose can be formed and knurled in the same manner desired shape.

In Figs. 1 tov3, I have illustrated a die which is provided with a circular bore extending therethrough. The central portion of the wall of the die about 'the bore is provided with parallel, longitudinally extending knurling teeth 10. The outer end 11 of the bore flares outwardly from the base of the teeth, to provide a clearance during operation. This flared portion of the bore is not a necessity, however, to the operation.

The hollow cylindrical blank A is provided with a reduced nozzle portion 12 and the blank, other than the nozzle is of a diameter slightly greater than the diameter of the bore of the die B. The original blank is shown in full lines with nozzle resting against theedge of the teeth 10 which is its position just previous to operation as shown in Fig. 1. The entrance end 13 of the bore is flared outwardly from the base of the teeth 10 to provide a clearance, and also to gradually reduce the blank to its final form as it passes into the central portion of the die. v

The cylindrical mandrel C fits snugly withthe inner end 30 thereof is tapered and bears against the upper inner wall of the nozzle 12 when positioned therewith during operation. The mandrel is formed with a shoulder 31 and the upper portion thereof, beyond the shoulder, is of a larger diameter than that within the blank. When the mandrel is placed within the blank, with its tapered end within the nozzle and the blank is pressed wit Tits shoulder against the C edge ofthe teeth inj'the die, the forming and provide the barrel or w by using a die and mandrel of the shoulder formed by the knurling operation is then ready to be per-V formed.

' The die is held stationary in a conventional manner and suitable power is applied against the mandrel to press the blank through the bore of the die. The blank is of larger diameter than the bore and consequently as it passes therethrough it will be reduced by the flared end 13'of the die to'the same diameter as the bore of the die. The knurling teeth project into the bore and knurl the outer surface of the reduced blank as it is pressed through the die.

Due to the reduction in the diameter of the blank, as it is pressed through the die and also to the knurling operation, the blank is elongated and gradually creeps up and the elongated portion thereof assumes substantially the shape shown in dotted lines in Fig. 1, as the blank is projected through the die. As the mandrel is of increased diameter with a shoulder extending between the two diam eter thereof, the blank creeping up will assume the same shape as that end of the mandrel upon which itcree'ps, forming the shoulder'31 when the operation is finished.

At the finish of the operation shown in Fig. 2, the shoulder of the mandrel will lie parallel with the wall of the flared bore, pressing the shoulder 14 formed on the blank therebetween to assure a neat, defined shoulder on the finished barrel. The mandrel, and knurled barrel thus formed, are then withdrawn from the die.

In Figs. 4 to 6 inclusive I have illustrated a form of mandrel which differs slightly from the one reviousl described, a blank sheet metal cy inder w ich is of larger diameter than that previously described being used. The die is the same as that illustrated in Figs. 1 to 3, and the forming and knurling operations are substantially the same as already described.

In this modification the mandrel G is of smaller diameter than the inside of the cylindrical blank A and differs from the mandrel previously described only in that it is of a continuous diameter, not having a shoulder and enlarged upper portion.

This mandrel is-placed within the nozzle of the blank, as in the previously described operation, and the blank is projected into the bore of the die B until the shoulder bears againstthe flared end 13 thereof as shown in Fig. 4. When insuch position the forming of the blank starts, the blank and mandrel are pressed into the bore of the die. As the cylinder is reduced, the'portion passing beyond the inner flared end'13 of the bore assumes the diameter of the central portion of the die,

. and a shoulder 20 corresponding to the angle of the flared bore is formed between the blank and its reduced portion. Y The teeth 10 knurl the outer wallof the formed portion-of the blank as it is pressed through the bore by the mandrel. The reduction in the diameter of the blank and the knurling and pressing performed on the blank, by the die and the mandrel, causes the blank to become elongated 'and that the finished article is the same as that produced in the previous method.

In this forming and knurling operation the blank is reduced to form the knurled portion of the barrel, while in the previously described method the blank is expanded to form the portion of the barrel above the knurled portion, but in both methods the forming and knurling operations take place during a sin- I gle movement of the blank and mandrel through the die.

In Figs. 7 and 8 I have illustrated a modified form of die having the entrance end of the bore of a slightly different form. The

.outer end 21 of the bore is cylindrical and of larger diameter than the central portion thereof, and an angular shoulder 22 joins these two portions. The blank and the mandrel are the same as described, and shown in Figs. 1 to 3 and the only difference from essential features previously described is in the die. The method of forming and knurling the blank is also the same as shown in Figs. 1 t0 3.

The cylindrical openingin the outer end 21 of the die is of substantially the same diameter as the blank, and the mandrel fits snugly within the blank with its tapered end 30 in the reduced end 12 thereof as set forth in the description of Figs. 1 to 3. When the mandrel is pressed into the toothed bore of the die a shoulder 14 is formed on the blank between the mandrel'and the shoulder 22 in the die, reducing the diameter of the blank as it enters the toothed bore. As the blank is projected through the die the portion thereof passing beyond the teeth is reduced in cylindrical form and the outer wall thereof is knurled. When the shoulder 31 of the mandrel reaches the position shown in Fig. 8 the shoulder 14 of the blank is pressed between the shoulder, 31 of the mandrel and,

the shoulder 22 of the die forming adefined angular shoulder on the now completed container.

The blank, as it is reduced and knurled creeps upwardly as shown in dotted lines in Fig. 7 and as described-f in. the previous operations.

The finished barrel. in}. the above methods of forming and knurliii'gjnarticleof the class described is the same. The knurled portion of the barrel is formed and knurled in the same manner in each method. 'lhe mannor of forming the shoulder and portion there-above differ in detail, but in each the same finished article as shown in Fig. 9 is produced.

lit it is desired to knurl a blank to provide a finished article having a uniform diameter above the nozzle portion, the die and mandrel illustrated in Figs. 4 to 6 can'be used and the blank can be pressed all the way through the bore of thedie in the same manner as e scribed previously, the teeth therein knurling the blank without any forming tahng place.

' Ablank couldalso be formed and knurled as illustrated in Figs; 4 to 6, by pressing the blank completely through the bore of the die. If desired, the ribs on the outer surface of the body which have been formed by the knurling operation can now be threaded, to receive an adjoining threaded section, such as a cap, when the body operated upon is to 1 be used as a container for a lubricant aispenser.

ln Fig. 10 l have illustrated several teeth in magnified form to illustrate the burred edges which are formed at each side of and projected from the teeth during the knurling operation. These edges provide an addi-v tional gripping surface enabling the operator to grasp the container more securely when he operates it.

Various changes in the details of the elements with which my improved method is applied can be made without departing from the spirit of my invention and the scope of the appended claims.

What I claim is ,J V

1. The method of fluting a tube which comprises drawing it through a gently tapering die having flutes with sharp corners and fiat bottoms, and not quite filling the flutes in said edges of said ribs.

die, to form ribs on the finished blank with fiat tops set in between two burrs along the 2.. The method of forming a tubular body fluted over a portion of its'length, having two inside and two outside diameters of approximately the same thiclmess throughout its length in a single operation, which comprises placing a blank having substantially the larger diameter, on a mandrel, forcing the smaller end of said mandrel and a portion of said blank through a ed, gently tapering die provided with a toothed bore, whereby the section of the blank passing through the die is reduced and fluted, leaving the up-v per blank portion of the original inside and outside diameters untouched by said die.

3. The method of reducing and dating a portion of a tubular body having two inside and two outside diameters and of substantial-. ly the same thichess throughout its length in a single operatiomwhich comprises drawof the ori 'nal inside and outsidediameters untouche by said die.

In testimony whereof, I have hereunto alffixed my signature this 10th day of April,

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